Drilling and production organizations operate data logging tools in their hydrocarbon production wells on a periodic basis to determine the down-hole ambient conditions in the well. The information recorded by the data logging tools is useful to determine oil and gas reserves and production plans.
Referring to FIG. 1, an illustrative prior art hydrocarbon production field 100 is shown. The field 100 illustratively depicts a slant-hole drilling well 102 and a horizontal drilling well 104. These types of wells include one or more curved portions which are directed to reach a target reservoir 112 that are not located directly below the drill site. Slant-hole wells 102 and horizontal wells 104 allows the driller to reach targeted reservoirs 112 that are not easily accessible due to geographical constraints (e.g., a marsh or lake), man-made constraints (e.g., environmentally protected areas), or shallow hydrocarbon reservoirs, any of which limit or otherwise prohibit a vertical drill site from being positioned directly above the target reservoir. Advantageously, directional drilling helps enable access to difficult-to-reach reservoirs 112 and allows the reservoirs to be drained more efficiently.
Slant-hole wells 102 and horizontal wells 104 each include a borehole or wellbore 106 having an initial vertical wellbore portion 108 and a curved wellbore portion 110, which directs the borehole 106 away from the vertical wellbore portion 108. The curved portion 110 can have a bend or curvature such that the drill will turn up to ninety degrees, as illustratively shown for the horizontal well 104 in FIG. 1. The curved portion 110 can be formed within a few feet in the horizontal well 104, while the slant-hole well 102 can make a turn that takes tens or hundreds or even thousands of feet to complete the turn.
Logging tools are primarily used to sense, monitor and obtain (i.e., record and/or transmit) data from the well, including data associated with the formation layers of the well and the wellbore's environmental conditions, which can be used for further analysis and/or determination of alarm conditions. The logging tools can also be used to perforate or plug reservoirs. In vertical wells, logging is typically performed by using a wireline attached to the logging tool. Alternatively, for wells having high-angled inclinations, implementing data logging tools in the wellbore is typically accomplished by using coiled tubing and/or drill piping which can be controlled by a rig or tractor system located at the surface of the drilling site.
The prior art logging tools can be cumbersome to implement in a wellbore 106. Therefore, there is a need for a self-driven and faster logging tool. Further, there is a need for an efficient driving tool that can propel or otherwise drive a logging tool that is attached to a wireline through a fluid-filled well. Moreover, there is a need for a self-propelled logging tool that can be easily provided in a well bore without having to use drill piping, coiled tubing and/or a tractor system which are less efficient and expensive to implement. Further, there is a need for a data logging tool that can traverse a well, e.g., a hydrocarbon production well, having inclinations greater than fifty degrees.